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* [Intel-gfx] [PATCH v2 1/2] drm/i915/userptr: add user_size limit check
@ 2020-01-16 20:31 Matthew Auld
  2020-01-16 20:31 ` [Intel-gfx] [PATCH v2 2/2] drm/i915/userptr: fix size calculation Matthew Auld
                   ` (4 more replies)
  0 siblings, 5 replies; 10+ messages in thread
From: Matthew Auld @ 2020-01-16 20:31 UTC (permalink / raw)
  To: intel-gfx

Don't allow a mismatch between obj->base.size/vma->size and the actual
number of pages for the backing store, which is limited to INT_MAX
pages.

Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
---
 drivers/gpu/drm/i915/gem/i915_gem_userptr.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index e5558af111e2..fef96a303d9d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -768,6 +768,18 @@ i915_gem_userptr_ioctl(struct drm_device *dev,
 	if (args->flags & ~(I915_USERPTR_READ_ONLY |
 			    I915_USERPTR_UNSYNCHRONIZED))
 		return -EINVAL;
+	/*
+	 * XXX: There is a prevalence of the assumption that we fit the
+	 * object's page count inside a 32bit _signed_ variable. Let's document
+	 * this and catch if we ever need to fix it. In the meantime, if you do
+	 * spot such a local variable, please consider fixing!
+	 */
+
+	if (args->user_size >> PAGE_SHIFT > INT_MAX)
+		return -E2BIG;
+
+	if (overflows_type(args->user_size, obj->base.size))
+		return -E2BIG;
 
 	if (!args->user_size)
 		return -EINVAL;
-- 
2.20.1

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^ permalink raw reply related	[flat|nested] 10+ messages in thread

end of thread, other threads:[~2020-01-20  3:49 UTC | newest]

Thread overview: 10+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-01-16 20:31 [Intel-gfx] [PATCH v2 1/2] drm/i915/userptr: add user_size limit check Matthew Auld
2020-01-16 20:31 ` [Intel-gfx] [PATCH v2 2/2] drm/i915/userptr: fix size calculation Matthew Auld
2020-01-16 21:19   ` Chris Wilson
2020-01-16 21:18 ` [Intel-gfx] [PATCH v2 1/2] drm/i915/userptr: add user_size limit check Chris Wilson
2020-01-17 11:51   ` Matthew Auld
2020-01-17 12:10     ` Chris Wilson
2020-01-17 13:08       ` Chris Wilson
2020-01-16 23:03 ` [Intel-gfx] ✓ Fi.CI.BAT: success for series starting with [v2,1/2] " Patchwork
2020-01-16 23:03 ` [Intel-gfx] ✗ Fi.CI.BUILD: warning " Patchwork
2020-01-20  3:49 ` [Intel-gfx] ✓ Fi.CI.IGT: success " Patchwork

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